According to the current state of the art, the demands placed on modern semifinished products result both from use and environmental properties and from cost aspects. Due to the pressure of competition, therefore, materials which allow economical production which are as far as possible free of waste appear attractive. Consequently, in many cases, workable materials, in particular, appear to be particularly advantageous by comparison with cast materials in the case of Cu alloys if complex functional components are being produced. However, the workability of Cu materials limits the use of highly valued properties of cast materials, among which the Cu--Sn materials play a particularly important role. They are distinguished, for example, by very high strength and hardness properties combined with very good corrosion properties and a generally excellent suitability for tribological requirements. The treatment and composition of the tin bronzes are described extremely extensively in the literature (e.g. K. Dies, Kupfer und Kupferlegierung in der Technik [Copper and copper alloy in engineering], Berlin 1967 page 504 ff.). This reference also deals with the possibility of achieving homogenous microstructures even in cast bronzes which contain up to about 15% by weight Sn by means of heat treatment. It is explained in that reference that homogenization treatments lead to pores (loc. cit. pp. 514-516), while, on the other hand, mechanical properties can be improved by homogenization, without there being any reference to this allowing cold-working (loc. cit. pp. 549 ff). Consequently, conventionally produced bronzes with a high tin content have to be homogenized in order to be worked, and therefore contain pores. It is known to the person skilled in the art that pores are undesirable for most technical applications. They form weak points under mechanical load and impair the working itself, or, after having been worked, at least prevent a flawless surface from being formed. For this reason, the prior art does not allow the use of cast bronzes as workable materials. Hitherto, it has been necessary to regard the contrast between workable and cast materials as impossible to overcome, although the availability of a workable material having the properties of a cast material has been regarded as desirable.